carb/fuel/ignition problem?

[AxtellZ]

Hi all,

my 74 260 with SU's has been bogged down :-(

Saturday when i turned off the choke a couple miles from work, lost all acceleration/power. Stopped & whacked the rear float bowl (the top was damp) and it ran fine the 26 miles home.

Its rained the last 3 days (car stayed inside), this morning i brought out the Z, got about 3 miles and "here we go again".

So i pull over, whack the bowls again, and take off, but still crappy power. Don't notice it at low speeds, but in 3rd & 4th gear at 3000-3500rpm, it acts like only half the engine is powering. I also noticed my amp meter jumped to +30, where it is normally just to the right of center?

So i figure i'll check floats, fuel filters, ignition...can anyone suggest where to start first? I really hate to replace entire systems just because i didn't check one item first!

Any and all suggestions welcome. Thanks everyone.

Jeremiah Axtell 73/240 74/260 both w/Su's

[hmsports]

Jeremiah,

You might want to check the jets in the float tops to make sure they are not sticking which would either stop all fuel from entering the float or maybe letting some in - this could explain why you are running ok at low RPM and then starving the engine at higher RPM. When you whacked the float, it may have unstuck it. Should be able to take them out and clean them.

Not sure about the amp jump. Could just be that your battery is getting old and/or your regulator needs to be adjusted/replaced. Check that your alternator is charging correctly and that your voltage regulator is working right too.

Hope that helps a little.

Rick

[AxtellZ]

You mean the grose-jet or assembly it replaces, correct?

Seems a year ago when i cleaned the carbs up, one of them did act a little goofy/sticky or something (they are the original style, NOT grose-jets). That would explain why it feels like half the motor is working certainly.

I can remove the float bowl cover with the carbs mounted without a problem right? (i've always done my tinkering when they were on the shop bench previously)

Thanks for the tip- sometimes my mind gets numb when i'm aggravated!

anyone know the going rate for grose-jets, and is ztherapy the only place to sell 'em lately? ThankZ!

[hmsports]

You can remove the float covers with the carbs on the car - they just need to be kind of jiggled/twisted/worked around a bit since they knock up against the carbs - at least on some models. Also make sure that the little pin that holds the float on doesn't fall out and get lost. One other thing to be careful of is not to rip the float gasket.

I've tried the grose jets before and didn't care for them. I've always had good luck with the stock ones - so I can't tell you the going price or even where to get them.

I know I'm going to get blasted by those who don't like them, but I will recommend Victoria British for their carburator rebuild kit. At only $12.95 per carb, you get a new jet with seat, new float gasket, new fuel hose and miscellaneous other gaskets. Or you can get a kit from MSA for about $70.

Let me know if this works.

[classic240z]

If you have an electric fuel pump, there may be a short in there somewhere. If it's an add-on and not fused that would definetly cause the amp meter to jump. It would shut the pump down also causing starvation. Another good cheap thing to do would be to change the fuel filter. If it's screwing up more in third and fourth that sounds like the culprit. Especialy if it started all at once. You never know when you're going to get bad gas. That's what it's there for Good luck

[peter]

I had a similar problem. If you have the electric fuel pump in the rear, it has an integral fuel filter. The bottom of the pump screws off, and there is a tiny cylinder type filter. Mine was completely corroded and gunked up.

It might seem that the floats are the problem, but mine would stall, or act like it wanted to, then start back up in a couple seconds.

I have a 73 240 with early SU's. I simply pulled the elec pump, bypassed it, and use only the mechanical pump on the engine. It solved my problem. One day I am going to clean up the elec pump and use it as a spare if the mechanical one ever fails.

Hope that helps.

peter

[AxtellZ]

Thanks everyone. Ended up working today, but did pull the float covers. All seems well, i think i'll chase filters tomorrow.

[AxtellZ]

Hi everyone. Been busy with "honey-do's", but finally got out to the Z. Started checking stuff out, and found a wire from the rear of the alternator ( that one lower & near the passenger side framerail) was basically half there- the bullet connector was barely connecting/arcing. No wonder my gauges would wander, and ignition was halfhearted. I semi-attatched the wire- don't have a connector on hand, and the car seems to run well.

However, my Right turn signal doesn't blink (left does) Maybe fried the blinker? Does each side have its own? Any guesses out there? Hopefully i can look in the daylight tomorrow, if it ever warms up again.. Thanks all:) JA

[2ManyZs]

Well, sounds like you are making progress (on the car that is). "Honey-do" list is all yours.....seems we all have a list of some kind don't we?

As to the turn signal dilemma, if one side is flashing and the other isn't it's not in the flasher. Have you checked the stalk itself? I have had the cover on the steering column move slightly which didn't allow the turn signal stalk to completely actuate the signal. If not there then check your signal assembly on the column, it could have dirt, or corrosion in it. Might no hurt to spray some contact cleaner in there just to be sure.